Mandrel.



No. 726,456. PATENTED APR. 28, 1903. H. PtElTTICEl MANDREL..

APPLIOATION FILED s221216. 1902.

I0 MODEL.

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HUGH PRENTICE, OF CLEVELAND, OHIO.

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SPECIFICATION formingpart of Letters Patent No. 726,456, dated April 28, 1903.

Applieationiiled September 16,1902. Serial No. 123,669. (No model.)

To @ZZ whom, L'z'; may con/00771,:

Be it known that I, HUGH PRENTICE, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Mandrels; and I do declare that the following is a full, clear, and eXact description of the invention, which will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to improvements in mandrels or cores used in the manufacture of sinuous tubes or forms havinga diaphragm and which tube or forms are used in the construction of water-tube boilers; and my irnprovement consists in the construction and arrangement of parts, all as hereinafter shown and described, and more particularly pointed out in the claims.

The objects of my improvement are, first, to provide a mandrel or core adapted to collapse or contract to smaller dimensions, and whereby it can be easily inserted into and withdrawn from the tube or rough form; second, to provide means for expanding the mandrel or core to the desired size when the mandrel is within the tube or form, and', third,

to provide means for carrying a diaphragm into the form with the mandrel or core and leaving the diaphragm in place therein when the mandrel is withdrawn.

In the accompanying drawings, Figure l is a side elevation of a mandrel or core and the mechanism associated therein, whereby the objects of my improvement are carried out. Fig. 2 is a horizontal sectional and plan view on line ne ai, Fig. l, looking down and showing a diaphragm held in the mandrel. Fig. 3 is an enlarged section in plan of the diaphragmsupporting plates and the sliding plates. Fig. 4 is a cross-sectional view on line y y of Figs. l and 3. Fig. 5 is a perspective view of a portion of a tube or rough form in the shape as it comes to the mandrel. Fig. 6 is a perspective View of the diaphragm which enters and is held and fastened in place within the tube or the form. Fig. 7 is a perspective view of a portion of the tube or form coinpleted. 1

Referring again to the drawings, wherein similar letters refer to similar parts, it will be seen that the mandrel or core comprises in part a pair of parallel oppositely-arranged plates A, having meeting faces a, constructed to grip and support a diaphragm B when said plates are forced or carried toward each other. Plates A are in turn supported between a pair of side bars or plates C and have a tapering or wedge-shape form end to end on their outside faces a', which abuts against a similar tapering face on the inside of bars or plates C. Plates C are adapted to slide back and forth on platesAto either expand or contract the mandrel from side to side and to hold or to release diaphragm B, and said movement is obtained by a pneumatic or hydraulic pressure operated piston F., which has a ram F, provided with an engaging head C, which interlocks withiingers C on the end bars or plates C.

An arm H, integral with the cylinder or piston-casing l, has an upright projection J, against which the ends of plates A abut and which serves to hold said plates against end movement.

Side bars or plates C have an additional function to that of expanding and contracting laterally and of clamping or releasing the diaphragm-supporting plates A in their sliding movement, and this is comprised in the construction of said plates C at their top and bottom edges, which are tapered or wedgeshaped to move dies or'blocks D outwardly to their proper or engaging position when in rough form L. Said blocks are separately arranged side by side the full length of plates C and rest upon or against the top and bottom tapering or inclined edges C2 of each side plate. The outer surface d of each block D is curved and shaped to provide a continuous sinuous surface when the blocks are grouped together upon plates C. Plates A. and C, with blocks D thereon, combine to make a complete mandrel, which is adapted to be inserted within a rough form, such as seen in Fig. 5. This can be only done when the piston is to the right and said blocks are brought nearer together from opposite sides, or, in other words, when the distance between the sinuous surfaces of the upper and lower blocks is less than the inner diameter or space of the rough form and when plates C are retreated from the sides to the center.

In operation the rough form, which is a me- IOO tallic tube rectangular in cross-section, is held or supported in the usual manner in the jaws or compressor-dies of the machine used in connection with the mandrel and which may be of any preferred make or construction and is therefore not shown. The mandrel, with diaphragm B held between plates A, is now brought forward, with its supporting-casing I, and is inserted into form L. Piston E is then forced forward or to the left under pneumatic or hydraulic pressure, the' supply land exhaust connections being had with the piston-chamber, as seen at M. This movement of the piston forces plates O to the left, expanding the same laterally, and spreads blocks D to their limit of movement within and against the inner sides of the tube or form. The compressordies of the machine now come together upon the outside of the tube or form and press the shell or walls of the tube to the sinuous form as outlined by the machine dies and mandrelblocks D, and thereby confine and fasten the diaphragm in place. The next step is to release and remove the mandrel and blocks, and this is easily accomplished by reason of my improved construction. Thus piston E is set into motion to slide plates C to the right, thereby relieving the pressure of the mandrel against the inner sides of the tube or form. Plates C free themselves from the side walls of the tube and also act in a similar manner to release blocks D from contact with the upper and lower walls. Pressure thus being relieved on the blocks and plates A and upon diaphragm B,plates C can be withdrawn from the sinuous formed tube, leaving blocks D and plates A free and loose therein to be taken out separately.

Diaphragm B is struck up at its opposite edges in the sinuous form that is finally produced in the tube, and it is inserted in this V2. In a mandrel adapted for use in a machine making serpentine tubes or forms having diaphragms, a set of plates constructed to support a diaphragm and provided with wedging-surfaces, in combination with a set of sliding plates mounted at either side of said diaphragm-supporting plates, substantially as described.

3. In a mandrel or serpentine-tube-forming machine, a set of diaphragm-supporting plates, a series of die-blocks for forming sinuous surfaces, a set of Wedging-plates constructed to engage said su pportin g-plates and said blocks, and means to slide said wedgingplates, substantially as described.

4:. In a mandrel adapted for the manufacture of sinuous tubes or forms having diaphragms, a set of supporting-plates for the diaphragms provided with wedge-faces, a series of die-blocks, and a set of sliding plates provided with wedge-faces opposite both said supporting-plates and said die-blocks, substantially as described.

5. A mandrel for sinuous-tube-forming machines comprising a setof sliding plates provided with wedge-surfaces at their top, bottom and side, a set of plates constructed to supporta diaphragm and provided with a wedge-surface adjacent the side wed ging-surfaces of said sliding plates, a series of dieblocks provided with wedge-surfaces and mounted upon said sliding lplates opposite its upper and lower wedge-surfaces, and means to operate said sliding plates, substantially as described.

6. A mandrel for sinuous-tube-forming machines comprising a set of sliding plates having tapering sides, a pair of diaphragm-supporting plates having tapering sides oppositely supported Within said set of sliding plates, a series of die blocks separately mounted upon said sliding plates, and a piston and ram having interlocking connection l with said sliding plates, substantially as described.

Witness my hand to the foregoing specification this 23d day of August, 1902.

HUGH PRENTICE. Witnesses:

R. B. MOSER, E. M. FISHER. 

